Several types of machines are known to the art for permitting the inspection of tire carcasses. For example, in Stoehr's U.S. Pat. No. 2,375,595, issued May 8, 1975, for "Tire-Casing Spreading And Inspecting Machine" the device includes a frame with a pair of spaced apart parallel rollers and a lifting mechanism for elevating the tire to its inspection position resting on the rollers. A pair of spreading hooks are located on either side of the tire and are adapted for engaging the tire beads to spread them apart. Fluid power means are provided for the lift system and for spreading the tire hooks.
The type of machine disclosed in Stoehr's Patent has several disadvantages. First, the lift system must be carefully controlled by the machine operator to properly place the tire on the machine. Second, the machine is not adapted for automatic inspection of the entire carcass because the hooks do not permit the tire to be rotated while the beads are spread. If inspection of more than one location is required, the hooks are disengaged from the beads, the tire is manually rotated on the support rollers and the hooks are re-engaged and activated to spread the beads at the new location. Thus, the inspection of the entire inside surface of the tire is a time-consuming process. Finally, the Stoehr device is unsatisfactory for use with radial tires because the spreading hooks tend to collapse the sidewalls of radial tires.
Another type of prior art tire inspecting machine is disclosed in Branick's U.S. Pat. No. 3,130,957, issued Apr. 28, 1964 for "Truck Tire Spreading and Inverting Device." The Branick machine also includes a frame and a lifting system for raising a tire to an inspection position. This device, however, differs substantially from the Stoehr machine in providing spreading hooks on each side of the tire which permits the tire to be rotated while the beads are spread. Rotation of the tire is made possible by an inverting head which is adapted to engage the tire tread between the spread rollers and push the tread toward the tire axis.
While the Branick system represents a significant improvement over the Stoehr device, it still does not overcome the problems inherent in the inspection of radial tires. The spreading hooks of Branick also tend to collapse the sidewalls of radial tires, and the alignment system of Branick's device still requires the exercise of caution by the machine operator to avoid dislodging the tire during elevation and inspection.
A tire spreading and inspecting device which overcomes the above-noted disadvantages of the prior art would be a significant advance in this technology.